Uniform shuttle tension



Nov. 30, 1943. w. P. ELLIS UNIFORM SHUTTLE TENSION Filed Sept. '7, 1942 INVENTOR. WILL/AM P. ELL/s.

v ATToeNEX Patented Nov. 30, 1943 UNIFORM SHUTTLE TENSION William P. Ellis, Decatur, Ga., assignor to Draper Corporation, Hopedale, Mass., at corporation-of Maine Application September 7, 1942, Serial No. 457,571

12 Claims.

This invention relates to threading blocks for loom shuttles, and more particularly to thread tensioning device for use therein.

The types of threading blocks to which my invention applies are those having a means incorporated therewith to frictionally engage the filling thread to produce tension thereinwhile it is being withdrawn from the shuttle.

In prior threading blocks of this type, asappliedto automatic filling replenishing looms, the friction means was made constantly to engage the filling thread in a predeterminedmanner to create a-fiXed amount of tension at this source. However, in the normal operation of a loom, the final tension in the running filling thread will be the result of the actions of several forces, some of which change in amount during the weaving process. No provision was made in such prior devices to regulate the effect of the friction means inaccordance with the requirements, of

the instantaneous conditions under which the loom was operating, to keep the final tension of the filling uniform.

It is an object of this invention to providefor use in an automatic filling replenishing loom a threading block having a means therein for. keeping the tension of the running filling thread uniform during the complete weaving operation.

It is another object of this invention to provide for an automatic filling replenishing loom:

a shuttle having a threading block in which there is a friction means to produce tension in the filling thread drawn therethrough, and to pro-- vide means for automatically controlling the amount of tension produced by the friction means to compensate for the variations in the effect of: other tension producing conditions imposed on the filling thread during theweaving operation, so that the resultant tension in the thread will remain substantially uniform.

It is a further object of this inventiontopro vide a threading block for a loom shuttle, said threading block having a longitudinal thread passage with a friction meansadjacent the entry thereto, and to provide a means adjacent the exit from such passage and connected to the friction means, and actuated by the filling thread derstood that'I do not wish to bev limited to the specific details shown, and in which:

Fig. 1 represents-apartial plan View of-ashuttle having incorporated therewith a threadingblock. made according to my; invention.

Fig. 2; represents an elevational view of asectionofv the threading block, taken alongthe line 22 of Fig. 1.

Fig. 3 represents anend elevation; of .,the threading block looking-from the point of the shuttle toward the filling carrier, and shows a fillingthread in placee-but not under tension.

.Fig. 4 represents the same end elevation as: shown in Fig. 3,;but indicatesthe disposition of theparts. when the-filling thread is undertension;

Fig. 5 represents a section of thethreading block in.elevation taken along the line 5-5 of Fig '1, and shows theposition of the parts-when the filling thread, is; under moderate tension.

Fig. 6 represents the same view as shown in. Fig. 5,. but indicates the-position of-the partswhenthe filling thread is under excessive tens sion.

.Fig; '7 represents an. end elevation ofthe threading blocklooking from the filling carrier and: toward the point, of the shuttle.

Fig. 8 represents aplan View of the bottomsurfacesof the threading block.

The drawingshows a usual type of" shuttle l havingan open interior portion 2 to accommodate -a filling carrier 3. A threading block 4, in-

serted. in the body of the shuttle, provides ameans for guiding the fillingthread F from the having curved upper, surfaces 6 and l which are formed to, lead the filling thread downwardly into alongitudinaLthread passage 8 substan-.

tially in alignment with the longitudinal axis of the shuttle, and also into engagement with a downwardly projecting born 9. A thread trap 4 maybe supplied at theentry endof the thread passage to retain the filling thread in a-propen operative position.

- During-the-weaving operationthe fillingthread is directed outwardly and forwardly relative to the shuttle. The shape of the horn 9, is. such that: under; these conditions the filling thread willrmove downwardly aljongthe horn. 9., intothe recess; I0,,and' through the side delivery. eye: of the shuttle. The threading block is completely threaded during the first; two picks after; the

transfer of a new filling carrier to the shuttle, and remains so until the filling is exhausted from the carrier.

It is essential to hold the running filling thread under tension so that it may properly be laid in the shed. Some tension results from the frictional resistanc derived from the travel of the thread over the fixed surfaces of the threading block. However sufiicient tension is not produced in this manner to satisfy the requirements of all types of operating conditions. Also it has been found that some filling threads require a greater amount of tension than can be obtained in this manner for the best results.

The tension of the filling thread is affected not only by the construction of the threading block, but also by conditions inherent in th normal weaving operation.

The filling carrier is usually wound with filling starting from the base end and moving progressively toward the tip. The full carrier is placed in the shuttle with the longitudinal axes of each in alignment, and with the tip of the shuttle adjacent the threading block. Therefore, as the filling is drawn from the shuttle, the thread at the tip end of the filling carrier will be unwound first, and the process will continue until the thread wound near the base end of the carrier is being used.

As the filling is drawn from the filling carrier, it will unwind circumferentially around it and pass longitudinally along the underlayers of filling thread and the body of the carrier until it reaches the threading block. As the filling thread on the carrier recedes farther from the tip it is drawn over a greater length of contacting, friction producing surfaces. The frictional drag on the issuing filling thread, and hence the tension therein, must, therefore, progressively increase from full to empty carrier. Because of this procedure, the filling thread is not laid in the shed under a uniform tension throughout the complete weaving operation, which may result in imperfect cloth being produced.

The tension in the filling thread also is affected when the shuttle is checked in the shuttle box at the end of a pick. The inertia of the filling thread being drawn from the carrier causes the thread to continue to unwind after the shuttle is stopped. If no mean are provided in the apparatus to hold the filling thread under tension at this time, the filling thread will continue to be drawn through the threading block to relieve any tension occurring in it. This will cause the filling to be in a slack condition when it is beaten into the fell, and may result in imperfect cloth.

Both of these conditions, as well as others affecting the tension in the filling thread, will be compensated for by the use of my invention.

As shown in the drawing, the friction means I provide may comprise a member Ii placed adjacent the entry to the longitudinal thread passage 8. Th friction member is mounted to move transversely of the thread passage to engage a filling thread between the member and the vertical wall I2 thereof.

Pressure is applied to the member I I by means of a. spring I3, which is, inserted through a hole I4 formed in the vertical wall l5 of the thread passage, and held in place by a set screw I6. By manipulating the set screw, the pressure exerted by the spring can be adjusted to cause the friction member to exert the desired initial pressure on the filling thread.

The friction member I! has attached to the lower end thereof a lever l? which rest in a channel it formed in the bottom surface I9 of the threading block. The lever I7 is disposed longitudinally of the threading blocl: in alignment with the thread passage 8.

The end of the lever El opposite to that attached to the friction member i l is bent upwardly at an angle, as at 2a, which causes a portion 2! of .it to pass across the end of the thread passage in a position to engage a filling thread running from the thread passage to the side delivery eye of the shuttle. The lever continues upwardly until the end 22 rests within a recess 23 formed in the top portion of the threading block.

a The top portion of the friction member II is bent at approximately a right angle to the longitudinal axis thereof as at 24 and is inserted in an opening 25 formed in the vertical wall E5 of the thread passage.

The friction member Ii and the lever II form a unitary-structure. It is mounted in the threading block so that the lever I I can rotate to a limited degree in the channel I8, and the recess 2'3 and the opening 25 afford sufficient clearance to the parts placed therein topermit the member II and the part 2| of the lever to rotate transversely of the thread passage.

Normally the spring I3 biases the friction member toward the wall I 2 of the thread passage, and hence the portion 2| of the lever I! is biased in the same direction, However, if the portion 2| of the lever is rotated toward the side delivery eye of the shuttle,it will cause the member II to act against the spring 53 and recede from the wall I2 to create a space between these elements.

As previously noted, the top surfaces 6 and 7 of the threading block are formed to lead a filling thread down into the longitudinal passage 8, and the horn 9 serves to guide it to the ide delivery eye 5. As the thread moves downwardly into the passage it engages the member H and the portion M of the lever I1, and remains in contact with these parts while it is withdrawn from the shuttle.

The friction member I I will cooperate with the wa l I2, through the action of the spring I3 to produce a frictional resistance to the travel of the thread through the threading block. The lever I1, underthe pull of the filling thread on the portion 2!, will cause the member II to act against the pressure of the spring 53 to relieve pressure on the filling thread and thereby reduce the tension therein. The spring i3 is strong enough to cause the filling thread being drawn from the side delivery eye always to retain a predetermined minimum amount of tension.

If the filling thread is afiected by other forces so that the tension in it exceeds the predetermined desirable value the lever I! will cause the eifect of the friction member ii to be diminished until the desired tension is again obtained. If the tension becomes excessive the member II will be moved far enough away from the Wall l2 so that it no longer will be operable to add to the tension in the thread. This condition is shown in Figs. 4 and 6. The degree to which the lever I1 is rotated will depend upon the amount of tension in the thread.

Conversely, when the tension in the filling thread is reduced below the point necessary to hold the action of the lever and the reaction of the spring in equilibrium, the spring !3 will force the member I I to increase pressure on the filling thread and thereby increase the friction dra ass-aces to produce more tension. Thus, when the shuttl'e comes' to rest in a shuttle box, the filling distributedthrough the shed willbe held undertonsion bythe action of the friction member, even though an excessive amount of filling thread has been unwound from the filling carrier in' the shuttle. Figs. 3 and 5' showthe positions'of the parts when the friction member is exerting maximum pressure on the filling thread.

Now it will be seen that the friction member I I has a range of effectiveness from zero to that of full spring pressure. The amount of tension producedby this member will be-the increment required to raise the'tension from that already existing in the filling thread from other causes to that required to achieve the predetermined desirable minimum value. The parts automaticall-y will be adjusted instantaneously to supply this increment. Likewise when the tension in the filling thread exceeds the desired amount, the parts will automatically be adjusted to reduce the tension created by the friction means.

Thus I have supplied a means to compensate for changes in tension occurring in the filling thread due to changing conditions of the parts during the weaving operation, and to hold the running filling thread at a uniform tension.

Having thus disclosed a preferred embodiment of my invention, I claim:

1. In a shuttle for an automatic filling replenishing loom, a threading block having a thread passage therein, means in said threading block positioned for frictional engagement with a filling thread, and means en aged by the filling thread and cooperating with the first mentioned means and responsive to variations the tension of said filling to vary the frictional drag of said first mentioned means on said filling thread to maintain a substantially uniform tension on the filling thread.

2. In a shuttle for an automatic filling replenishing loom, a threading block having a thread passage therein, means in said threading block positioned for frictional engagement with a filling thread, and means cooperating with the first mentioned means and responsive to variations in the tension of the filling thread to vary inversely the frictional drag of the first mentioned means on the filling thread to cause substantially uniform tension to be maintained on the filling thread.

3. In a shuttle for an automatic filling replenishing loom, a threading block having a thread passage therein, means in said threading block positioned for frictional engagement with a filling thread, and means engaged by the filling thread and responsive to variations in the ten sion of the filling thread and cooperating with the first mentioned means to vary the frictional drag between said first mentioned means and the filling thread.

4. In a loom shuttle, a separable threading block having a thread passage therein, a friction means in said passage and positioned normally to engage a filling thread to provide a predetermined frictio-nal drag and means in said threading block cooperating with said friction means and actuated by said filling thread to cause the said friction means to be effective to vary frictional drag on said filling thread in inverse relationship to the tension therein.

5. In a loom shuttle, a separable threading block having a thread passage therein, a friction means in said passage and positioned resiliently to press a filling thread between the said friction means and awall of: said passage, and means in said threading blockcooperating with said friction means and actuated by said filling-thread to cause the pressure of said friction means to be varied on-saidlfilling thread to maintain substantially uniform tension on said fillingthread.

6; In a threading block for use in a loom shuttle, a longitudinal thread passage, a resiliently mounted friction means placed transversely of said passage and positioned to press afilling thread between said friction means and a wall of said passage, and means in said threading block cooperating with said friction means and actuated by said filling thread to cause said friction means to reduce-pressure on said filling thread upon increase of tension therein.

'7. In an automatic filling replenishing loom,- a shuttle, a supply of filling thread in said shuttle, a threading block in said shuttle through which said filling thread is drawn during a weaving operation, means in said block for frictionally engaging the filling thread to tension said thread during the said weaving operation, and means in said threading block operable to compensate for the variations of tension in said filling thread to hold said filling thread under a substantially uniform tension during the weaving operation.

8. In a threading block for a loom shuttle, a longitudinal thread passage having an entry end and an exit end, means positioned adjacent said entry end to frictionally engage a filling thread running through said passage, means positioned adjacent said exit end and having a portion connected to said first means, said second means being constructed and arranged to be engaged and actuated by said filling thread to control the effect of said first means in accordance with variations in tension in said filling thread to maintain the tension of said filling thread substantially uniform.

9. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed friction means placed transversely of said passage and positioned to engage a filling thread between said means and a side wall of said passage, a lever member operably positioned in said threading block and having a portion connected to the said friction means and another portion engaging the filling thread, said lever member being constructed and arranged so that it will cooperate with the filling thread and the said friction means to cause the said friction means to engage the filling thread with a pressure inversely proportional to the tension in said thread.

10. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed friction means placed transversely of said passage and positioned to press a filling thread between said means and a side wall of said passage, a lever member operably mounted in said threading block and having a portion connected to said friction means and another portion engaging the filling thread at a point spaced apart from said friction means, said lever member being constructed and arranged to cooperate with the filling thread and the friction means to cause said means to decrease pressure on the filling thread as the tension therein is increased, said spring pressed friction means being operable to increase pressure on the filling thread as the tension therein is decreased.

11. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed friction means placed transversely of said passage and positioned to engage a filling thread betWeen said means and a side Wall of said passage; a lever member positioned in said threading block parallel to said thread passage and having one end connected to said friction means and the other end but to extend transversely of the thread passage to engage a filling thread placed therein, said lever member being mounted for limited rotary movement relative to said passage, said lever member being constructed and arranged to be actuated by the filling thread'to control'the pressure of said friction means thereon in inverse relationship to the tension in said thread.

12. In a, threading block for a loom shuttle, a longitudinal thread passage, a thread tension controlling device in said threading block comprising a spring pressed friction member movable transversely of said passage and operable to engage a filling thread between said member and a Wall of said passage, said member having an extending portion on the lower end thereof positioned longitudinally of the threading block in alignment with the thread passage, an upturned end portion on said extending portion constructed and arranged to extend across the terminus of said longitudinal thread passage in a position to engage a filling thread passing through the threading block, said controlling device being mounted for limited rotary movement in said threading block and being constructed and arranged to be actuated by the filling thread to cause said friction member to engage the filling 15 thread with a pressure inversely proportional to the tension in said thread.

WILLIAM P. ELLIS. 

